The present disclosure relates to an image pickup unit suitable for use in X-ray photography for medical and nondestructive inspection applications for example, and an image pickup display system using such an image pickup unit.
Recently, there has been developed an image pickup unit such as a human chest X-ray photography unit, which acquires an image based on radiation rays in a form of an electric signal without any radiographic film. Such an image pickup unit has pixels each of which includes a photoelectric conversion device and a field-effect thin film transistor (TFT). Signal charges accumulated in a pixel are read out with a pixel circuit including a transistor to acquire an electric signal based on the quantity of radiation rays.
Examples of the photoelectric conversion device used in such an image pickup unit include a positive intrinsic negative (PIN) photodiode. The PIN photodiode has a structure where a so-called i-type semiconductor layer (intrinsic semiconductor layer) is interposed between a p-type semiconductor layer and an n-type semiconductor layer, which may output signal charges having the amount corresponding to the quantity of incident light (for example, see Japanese Unexamined Patent Application Publication Nos. 2008-277710 and 2011-14752).